350 chev streetable engine build

Hey all. I have been lurking around this site for a couple years and I am amazed by the vast amount of knowledge here. I would like to ask you pros for your opinions on the best way to build my engine?
First off I will tell you what I am putting it in.
I am building a Steel bodied T bucket. I have a turbo 350 trans and plan on a 2800 stall converter. I have a 3.50 ratio rear end and 29 x 15.5 M/T Sportsman Pro tires.
The engine I am starting with is a 350 my brother ( he passed away 4 years ago so I don't have much info on it ) was building. He was building a race motor out of it so it has I am guessing 11:1 pistons. The bottom end is all done, so I was hoping to just re-assemble it with about 9.5 to 1 pistons so I can run it on pump gas.
Head options I have:
-1.94 camel hump heads- need hardened seats and rebuild.
-882 heads that need rebuild.
-heads on a '71 chev truck engine I have for rebuild.
-looking at buying a set of ProComp alluminum heads.(Probably a couple hundred more than rebuilding the camel humps)
The other engine parts I have to work with are:
-Edelbrock 600 carb
-Edelbrock performer Air Gap intake
-Electronic ignition (would buy an MSD box)
-I was thinking about a Thumper Cam (they sound cool!)
-1 5/8" sprint car headers
I am looking to build this as economical as possible. I'm not trying to hit 500HP. I just want a good streetable engine that runs on pump gas that I can build with mainly the parts I have and a minimal investment.
Thanks for your help in advance.
Brad.

I'm cheap, but not so cheap that I would begin a build with the heads or intake manifold you have on hand. Begin the hunt for L31 Vortec heads, casting number 12558062 or 10239906. They were used on '96-'99 Chevy trucks with the L31 5700 Vortec motor and are the best flowing production heads that Chevy ever produced. The 062's and some of the 906's had induction hardened seats, while some of the 906's used in heavy duty trucks got pressed in exhaust seats. Pin the studs, install new seals, put a 5-angle valve job on 'em and use CompCams drop-in beehive valve springs and retainers matched to the cam of choice. These heads use rail rockers, so if you find a set in a boneyard, get the rockers and valve covers with 'em. I have found 'em on craigslist and ebay. Don't be hoodwinked into buying some fosdick heads that somebody says are "vortec" heads, look for genuine GM heads with either of the casting numbers I listed.

Also, begin your search for an Edelbrock Performer RPM Vortec #7116 or Performer RPM Air Gap Vortec #7516 intake manifold. Either of these manifolds will make more power and torque from idle to 6000 than any other manifold you could bolt on the motor, even with your 600 carb. Both are Vortec-specific. Nothing wrong with a used manifold if you can find one. Again, check craigslist and ebay. Sell that weak-suck Performer Air Gap to someone who doesn't know any better.

Use this piston with the Vortec 64cc heads for a static compression ratio of 9.6:1....
http://kb-silvolite.com/performance....tails&P_id=155
KB's use an offset dish in a D-cup configuration that allows a generous flat pad on the crown to mate up with the underside of the head to make a good squish.

Cut the block decks to 9.001" for a zero piston deck height and use a 0.039" or 0.040" compressed head gasket for the correct squish to prevent detonation on pump gas.

1 5/8" long tube, equal length headers.

CompCams hydraulic flat tappet cam.....
http://www.compcams.com/Cam_Specs/Ca...x?csid=87&sb=0

Makes 427 hp @ 5500 and 444 ft/lbs @ 4000.

Tech, thats pretty close to my motor.
your good!!!

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Originally Posted by techinspector1

I'm cheap, but not so cheap that I would begin a build with the heads or intake manifold you have on hand. Begin the hunt for L31 Vortec heads, casting number 12558062 or 10239906. They were used on '96-'99 Chevy trucks with the L31 5700 Vortec motor and are the best flowing production heads that Chevy ever produced. The 062's and some of the 906's had induction hardened seats, while some of the 906's used in heavy duty trucks got pressed in exhaust seats. Pin the studs, install new seals, put a 5-angle valve job on 'em and use CompCams drop-in beehive valve springs and retainers matched to the cam of choice. These heads use rail rockers, so if you find a set in a boneyard, get the rockers and valve covers with 'em. I have found 'em on craigslist and ebay. Don't be hoodwinked into buying some fosdick heads that somebody says are "vortec" heads, look for genuine GM heads with either of the casting numbers I listed.

Also, begin your search for an Edelbrock Performer RPM Vortec #7116 or Performer RPM Air Gap Vortec #7516 intake manifold. Either of these manifolds will make more power and torque from idle to 6000 than any other manifold you could bolt on the motor, even with your 600 carb. Both are Vortec-specific. Nothing wrong with a used manifold if you can find one. Again, check craigslist and ebay. Sell that weak-suck Performer Air Gap to someone who doesn't know any better.

Use this piston with the Vortec 64cc heads for a static compression ratio of 9.6:1....
http://kb-silvolite.com/performance....tails&P_id=155
KB's use an offset dish in a D-cup configuration that allows a generous flat pad on the crown to mate up with the underside of the head to make a good squish.

Cut the block decks to 9.001" for a zero piston deck height and use a 0.039" or 0.040" compressed head gasket for the correct squish to prevent detonation on pump gas.

1 5/8" long tube, equal length headers.

CompCams hydraulic flat tappet cam.....
http://www.compcams.com/Cam_Specs/Ca...x?csid=87&sb=0

Makes 427 hp @ 5500 and 444 ft/lbs @ 4000.

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That sounds like a nicely balanced combo. The only thing I would change would be primary tube size on the headers. I am a fan of bigger pipes. I'd go 1 3/4"

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Originally Posted by Flipper_1938

That sounds like a nicely balanced combo. The only thing I would change would be primary tube size on the headers. I am a fan of bigger pipes. I'd go 1 3/4"

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You wouldn't if you had seen the torque loss I saw with bigger pipes.

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Originally Posted by techinspector1

You wouldn't if you had seen the torque loss I saw with bigger pipes.

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I run a 3500 stall converter. I guess low end torque never figures in. It jumps when I gas it at whatever speed that may be.

I have 1 3/4 primaries, feeding into 3 1/2 collectors, into 3 1/2 pipes, and run flowmaster world of outlaw spec mufflers.

It breathes nicely and sounds GOOOOOD!

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Originally Posted by TO-FAST-4U

looks like you have some good parts all ready use them and save some money . most all them vortec heads are cracked in the junk yard . and the new ones need lots of work to be used on a hot rod . don't wast you time and money on vortec junk heads .

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Junk? I think you are trying to pull someone's chain. LOL! I don't use junkyard parts, so I cannot respond to any cracking issues. But they are not junk. They flow better than the old fuelie heads and numerous other GM castings. They have much improved combustion chambers that employ GM's fast-burn technology. And they are not very expensive if you buy them new when you compare them with the cost of aftermarket iron heads. They need some machining if you are going to run over .480 lift, but they are a superior head with a lot of hp potential. All they need is a little bowl blending like most heads do. Check out the RHS versions which have already been machined for higher lift cams.

Quote:

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Originally Posted by TO-FAST-4U

looks like you have some good parts all ready use them and save some money . most all them vortec heads are cracked in the junk yard . and the new ones need lots of work to be used on a hot rod . don't wast you time and money on vortec junk heads .

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i have check many of them heads .the way i see it. is there are the ones that are crack and the ones that are going to crack so? i have been told that they did rework the casting ? there will be work to make them work like the intake bolt hole two on each end .as well as spring studs milling them could need guids new valve there not that cheap in the long run .they are a weak casting off the bat that could crack when all done .i just buy the after market casting

Hey Guys. Thanks for all the info. Tech, I appreciate your knowledge on this and I think I will go with the vortec heads. What are your thoughts on the vortec heads cracking like Pat says?
Thanks, Brad

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Originally Posted by bad brad

Hey Guys. Thanks for all the info. Tech, I appreciate your knowledge on this and I think I will go with the vortec heads. What are your thoughts on the vortec heads cracking like Pat says?
Thanks, Brad

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well i am not taking anything away from Tech:3dSMILE: . i do have a machine shop . I look at heads every day .all i am telling you the last 8 sets i have seen in my shop 4 set of them have been junk .that all so go s for the dodge magum heads **) if you buy the gm heads if not all set up to go. your going to spend good money to make them work. on top of the machine work they will need . i use the aftermarket heads .for the stock vtec heads. the last set of GM vtech heads i did .i hot tank and mag 3 sets to find one set that was good. he had over $60.00 just in checking junk. the junk yard did not cover that . i get paid the same to check junk or good parts but it gets old playing that game . so you could be out some coin just playing this game. then they needed a mill job. then .valve job .new seals .re shim the stock springs and for 300. more the guy could of had new heads. new valves. new springs .locks .retainers. now if them heads he had needed valves or guilde work it would of been a draw or more then all new.they were for stock chevy truck. now add to drilling the heads for a intake bolts .setting the heads up for screw in studs or pinning the old studs and seting them up for new hi lift springs new valves. just alot of money and time in a weak casting?

I would take and blend Tech and Pats information into one. Do what Tech said and buy the new aftermarket Vortec heads as Pat mentioned. They have been around engines long enough to have dealt with all sorts of combinations of street and strip motors. Since this is a street motor, I dont believe in making them sound like a drag car and having a huge cam, aftermarket aluminum heads, huge stall, etc etc. Street motors do just fine with what Tech posted above...
Now one thing I have a question on if you dont mind me asking in your thread is, instead of better performance over a old style motor and head combo and a new vortec style head and intake combo, will the Vortec style get better fuel milage if both motors ran the same internals, compression, cam, rear end gear, tranny, etc? Reason I ask is because I am building this NON vortec 350 for my 63 Chevy II wagon that I am going to use as my DAILY driver so trying to get nice performance but mostly reliability and fuel milage out of it. I dont want to build this motor and then find out that I could have went with the Vortec motor for only $300-$400 more and had a much better performing motor with better fuel milage but then again I wont spend an extra $1000 to have a Vortec motor when I have a good one sitting here now.

Another option would be to purchase a new set of S/R Torquer heads. They do not have the new chamber design that the Vortecs have but they are sold new at a reasonable price.

The pile you have will probably run just fine. Not make the ultimate in power but with a light weight T Bucket it will just waste the MT's anyway. The Thumper would be my choice just to be cool sounding. I don't think you will need the 3000 converter with the light weight car but if you have it run it. I got one in my 41 Willys and love it.

It will be quick enough to put skid marks in your shorts as well as on the pavement as it is.

a light car with a thumper cam it will need some stall**)

Good onfo here.


Jay

Yeh a set of 1 3/4's will be to big for that motor of course they'll bolt on but with that said dosent make them a good choice will give up alot of low and mid range power witch is were your going to live with this combo rpm wise. 1 5/8 will be just right

A good rule of thumb is to keep header pipe diameter as close to the exhaust valve diameter. Use the 1 5/8" unless you plan on over 500 hp.

Hey Tech. I have bought a set of rebuilt vortec heads from an engine rebuilder. I am now looking at cams and pistons. Which thumpr cam would you use or would you only use the one you suggested. Also, are the KB pistons the only ones you would use or are there any others to consider? And do you know how high a lift I can go with the vortec heads?
Thanks in advance, Brad.

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Originally Posted by bad brad

I am looking to build this as economical as possible. I'm not trying to hit 500HP. I just want a good streetable engine that runs on pump gas that I can build with mainly the parts I have and a minimal investment.

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OK, this is the hard way to do it, picking a cam and then setting the static compression ratio to fit the cam. There are way more cam choices than there are piston choices, but I'm trying to start with a Thumpr for you. Here is the cheapest 1.560" compression height piston I can find that has a reasonably wide, flat perimeter to make squish against the underside of the cylinder head and a properly sized dish to make the right static compression ratio with the Vortec heads.
http://www.summitracing.com/parts/STL-H670CP30/
Production cylinder heads will usually pour a little larger than the published chamber volume. Here's how these pistons work out with different chamber volumes:
64 9.77:1
65 9.66:1
66 9.56:1
What I was trying to do is get a static compression ratio that would work with the middle of the road Mutha-Thumpr, #12-601-4 and generate a dynamic compression ratio that would be compatible with pump gas.

You want to cut the block deck height to 9.010" and use a GM 10105117 head gasket. That will put the piston deck height at 0.010" and the squish at 0.038".

Cam: 12-601-4 flat tappet hydraulic Mutha-Thumpr. Intake centerline 102 degrees ATDC, Exhaust centerline 112 degrees BTDC, Lobe Separation Angle 107 degrees. Intake lift 0.489", exhaust lift 0.476". Intake opens 15.5 degrees BTDC, intake closes 39.5 degrees ABDC, exhaust opens 56.5 degrees BBDC, exhaust closes 12.5 degrees ATDC.
http://www.compcams.com/Cam_Specs/Ca...?csid=108&sb=0

Heads: Pin the rocker studs with this kit....
http://www.jegs.com/p/Mr-Gasket/Mr-G...49537/10002/-1
Must replace valve springs to use this cam. Can use conventional outer with spiral wound damper, but will probably have to cut the guide to a smaller diameter because the inner diameter of the damper will not clear the guide. Most popular would be to cut the guide to 0.530" for use with PC-type valve seals. Spring seats in the heads are cut to +/- 1.250".
Use these springs....(1.254" O.D.)
http://www.summitracing.com/parts/CCA-981-16/
And these 7 degree retainers....
http://www.summitracing.com/search/?...20742-16&dds=1
And these locks....
http://www.summitracing.com/parts/CCA-648-16/
Guide cutter....
http://www.summitracing.com/parts/CCA-4726/
Guide cutter arbor....
http://www.summitracing.com/parts/CCA-4732/

Heads, Plan B....
Use Comp beehive springs that require no cutting....
http://www.summitracing.com/parts/CCA-26981-16/
With these 7 degree retainers....
http://www.summitracing.com/parts/CCA-787-16/
And these locks....
http://www.summitracing.com/parts/CCA-648-16/

Rockers: Must use rail rockers unless you want to pull the pressed-in studs and machine the pads and tap the holes for screw-in studs and guide plates. You use one or the other, rail rockers with no guide plates or conventional rockers with guide plates. Using rail rockers with guide plates will break something. If you want to go with guide plates, forget the stud pinning kit I linked above. Wanna go cheap? Rescue stock 1.5 rail rockers from the boneyard. Ran this DynoSim with 600 carb and RPM intake....using a standard Performer will drop 38 hp....
RPM HP TQ
2000 139 362
2500 181 381
3000 230 402
3500 284 426
4000 335 439
4500 381 444
5000 415 436
5500 431 412
6000 419 367

Thanks Tech. How high a lift can I go with?

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Originally Posted by bad brad

Thanks Tech. How high a lift can I go with?

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Beehives install at 1.700". Max valve lift 0.525" @ 1.175". Coil bind at 1.115".
981's install at 1.700". Max valve lift 0.490" @ 1.210". Coil bind at 1.150".

Hey Tech. I need some more help please. I have talked to a couple of local engine builders. I do value your advice though! I have purchased a comp cams H270 (PART #12-211-2) First, do you think I will have to modify the heads for this lift? Second, the one builder recommends Mahle hypereutectic pistons over the KBs. What do you think of them? Third, the other builder (builds stock car motors) says to use the pistons that are in the engine. He figues they are 10.5 to 1 as they have .100 domes. Is there a way to use a thicker head gasket with these pistons with the vortec heads to bring down the ratio?
Thanks
Brad

OK, first, let's bring everyone up to speed on this cam....
http://www.compcams.com/Cam_Specs/Ca...x?csid=78&sb=0

Any competent cam grinder will tell you that you need a minimum of 0.050" clearance to prevent coil bind on the valve springs at max valve lift. That means that you should be able to insert a 0.010" feeler gauge blade between each of the 5 coil spaces in the spring with the valve at full lift. If you can do that with a valve lift of 0.470", go fo it. If not, you'll have to change springs. The other thing you need to check (and this is the most frequently given limit on Vortec heads) is the clearance between the bottom of the valve retainer and the top of the valve seal. Most cam grinders will suggest 1/16" to 1/8" clearance with the valve at full lift. If you have that much clearance with the 0.470" lift cam, go for it. If not, you'll need to change springs or do a ghetto grind on the bottoms of the retainers. Even at that, using the stock Vortec springs isn't gonna do much for you in a performance format. Seems I remember the "over the nose" pressure is something like 240 lbs, so they're gonna float the valves pretty easily if you wind the motor very tight.

Comp calls for spring numbers 981 or 983 with that cam, so heed what they are suggesting or wing it yourself. It's up to you. I gave you all the tool numbers earlier in this thread.

A 350 Chevy with 0.100" dome pistons and 64cc heads will make 11.80:1 static compression ratio. Better send that machinist back to school.

Thanks Tech. I will do an assembly of it and check out the clearances. I also was doubtful of the comp ratio of those pistons. Thanks for the input.
Brad

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Originally Posted by bad brad

Hey all. I have been lurking around this site for a couple years and I am amazed by the vast amount of knowledge here. I would like to ask you pros for your opinions on the best way to build my engine?
First off I will tell you what I am putting it in.
I am building a Steel bodied T bucket. I have a turbo 350 trans and plan on a 2800 stall converter. I have a 3.50 ratio rear end and 29 x 15.5 M/T Sportsman Pro tires.
The engine I am starting with is a 350 my brother ( he passed away 4 years ago so I don't have much info on it ) was building. He was building a race motor out of it so it has I am guessing 11:1 pistons. The bottom end is all done, so I was hoping to just re-assemble it with about 9.5 to 1 pistons so I can run it on pump gas.
Head options I have:
-1.94 camel hump heads- need hardened seats and rebuild.
-882 heads that need rebuild.
-heads on a '71 chev truck engine I have for rebuild.
-looking at buying a set of ProComp alluminum heads.(Probably a couple hundred more than rebuilding the camel humps)
The other engine parts I have to work with are:
-Edelbrock 600 carb
-Edelbrock performer Air Gap intake
-Electronic ignition (would buy an MSD box)
-I was thinking about a Thumper Cam (they sound cool!)
-1 5/8" sprint car headers
I am looking to build this as economical as possible. I'm not trying to hit 500HP. I just want a good streetable engine that runs on pump gas that I can build with mainly the parts I have and a minimal investment.
Thanks for your help in advance.
Brad.

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11:1 is pump gas friendly, just make sure its premium.

Hey guys. A new development here! Today I picked up a 1998 vortec 350 that has 2 new 906 heads( 1 hour run time !!!) with 2 slapping pistons for $500. Crank has some wear but will clean up. I have heard of some good things about building these engines. Should I be building this engine or continuing with the origional plan?
Thanks
Brad